Issue with MC34VR5100A1EP chip

[minalnemade]

Hi,

       We have build custom board with LS1012A and PMIC chip MC34VR5100A1EP. We are facing issue of VSNVS output from PMIC chip. We are providing 3.3V input to PMIC chip but we are not getting VSNVS output inspite of Vin voltage > 3.1V. We have connected VSNVS output to EN pin of PMIC chip. As VSNVS output is missing PMIC chip is not getting enabled and hence it is not generating any output voltages. As per data-sheet of PMIC chip VSNVS output can not be disabled and is generated after Vin voltage > 3.1V (UVDET). Inspite of this condition being met we observed that VSNVS output is not generated by PMIC chip. We are not using coin cell battery input and hence LICELL input of PMIC chip is bypassed to ground through 0.1uf capacitor. All connections of PMIC chip are as per the reference design of LS1012AFRDM. Please let's know what could be the issue.

regards

Minal

[r8070z]

Have a great day,

Yes VSNVS is an always on regulator. I can suggest only checking the 0.1uf and 0,47uf capacitors and connection from the VSNVS pin to the external circuit only. You can get more useful answer if you ask PMIC related question in the Power Management community https://community.nxp.com/community/Power-Management

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